PROJECT SUMMARY/ABSTRACT The burden of HIV is far from equally distributed in the US. Key metrics of the HIV epidemic continue to be predicted by demographic factors (e.g., race, gender, sexual orientation, geography). At the intersection of these determinants is one of the highest-risk groups for HIV infection in the world, and this project's population of interest: Black and Latino gay, bisexual, and other men who have sex with men (GBM) in the US South. Such individuals endure multiple forms of stigma (e.g., racism, homophobia), which elevate stress and erode health. Thus, applying theories of intersectionality and minority stress to epidemiological and intervention research may provide novel insights and tools to support the health of this vulnerable subgroup. The proposed training plan will provide Skyler Jackson, PhD, with the essential knowledge and skills necessary to develop independence and forge a career advancing scientific knowledge concerning intersectional stigma as a determinant of mental and sexual health risk among Black and Latino GBM. The goals of this mentored award are summarized by three distinct training objectives: (1) to gain skills using contemporary epidemiological methods, (2) to learn best practices in qualitative, community-engaged intervention development, and (3) to develop foundational skills in clinical trials methodology. Dr. Jackson will put these aims into practice via three novel, interrelated research projects, in which he will: (1) use longitudinal data from a prospective cohort study to identify mediators and moderators of the association between intersectional stigma and mental/sexual health among GBM of color across distinct US geographies, (2) combine these findings with data from formative research (e.g., 30 interviews with GBM of color and community stakeholders in Middle Tennessee) to modify an existing evidence-based stigma-coping health intervention for GBM?using the 8-phase ADAPT-ITT model?thereby increasing its cultural and geographic relevance to the mental and sexual health of Southern Black and Latino GBM, and (3) pilot this intersectional, culturally-responsive health intervention for young Southern Black and Latino GBM (n = 30; across two sequential cohorts) in collaboration with a community partner in Middle Tennessee. To develop his independence as a scientist, Dr. Jackson will be mentored by John Pachankis, PhD (Yale University), with support from additional co-mentors: Lisa Bowleg, PhD (George Washington University), Dustin Duncan, ScD (New York University), and Mark Hatzenbuehler, PhD (Columbia University). Where knowledge gaps remain, Dr. Jackson will engage in carefully selected training activities?e.g., grant writing, coursework, conferences, and manuscript preparation. Much of this training will be made possible by institutional support available through Dr. Jackson's joint affiliation with the Yale Center for Interdisciplinary Research on AIDS, Yale School of Public Health (YSPH), and YSPH Esteem Research Lab in New York City. Dr. Jackson's K01 training plan is optimized to address his training gaps and prepare him for a productive career as an independent scientist.